Connection-responsive push-to-talk

Abstract

Apparatus and method to monitor the coupling of one or two audio devices and to augment the function of a PTT switch to causes the PTT function of one audio device to be engaged regardless of which of the two operated positions into which the switch is moved in response to there being only the one audio device coupled to the apparatus and in response to the one audio device being a radio, to cause the PTT function of either one of two audio devices to be selected to be engaged depending on which operated position to which the PTT switch is moved in response to there being only one audio device in the form of an intercom system (ICS) coupled to the apparatus with the other audio device in the form of a radio being coupled through the ICS, and to allow the PTT to be used to select the PTT function of either one of two audio devices to be engaged in response to there being two audio devices in the form of radios coupled to the apparatus.

1. An apparatus comprising:
 a push-to-talk (PTT) switch having a center position, operable to a first non-center position from the center position to couple a common contact of the PTT switch to a first contact of the PTT switch, and operable to a second non-center position from the center position to couple a common contact of the PTT switch to a second contact of the PTT switch, wherein the common contact is coupled to a voltage level and wherein the PTT switch operates as a momentary switch when operated to the first and second non-center positions with a biasing towards the center position; 
 a first connector to enable the coupling of a first audio device to the apparatus, having a first PTT contact coupled to the first contact of the PTT switch; 
 a second connector to enable the coupling of a second audio device to the apparatus, having a second PTT contact coupled to the second contact of the PTT switch; 
 a PTT circuit coupled to the first and second contacts of the PTT switch, and structured to:
 monitor a first connect contact of the first connector to detect an indication of the first audio device being coupled to the first connector; 
 couple the second PTT contact to the voltage level to which the common contact of the PTT switch is coupled in response to detecting that the PTT switch has been operated to the first non-center position to couple the first contact of the PTT switch to the common contact at a time when the PTT circuit detects no indication of the first audio device being coupled to the first connector; and 
 refrain from coupling the second PTT contact to the voltage level to which the common contact of the PTT switch is coupled in response to detecting that the PTT switch has been operated to the first non-center position at a time when the PTT circuit detects an indication of the first audio device being coupled to the first connector. 
 
 
     
     
       2. The apparatus of  claim 1 , wherein the voltage level to which the common contact of the PTT switch is coupled is a ground conveyed by a ground conductor. 
     
     
       3. The apparatus of  claim 2 , wherein the indication of the first audio device being coupled to the first connector is the first connect contact being coupled to the ground conveyed by the ground conductor, and wherein the first audio device is a radio. 
     
     
       4. The apparatus of  claim 1 , wherein the PTT circuit is further structured to:
 monitor a second connect contact of the second connector to detect an indication of the second audio device being an intercom system (ICS) coupled to the second connector; and 
 modify the manner in which the PTT circuit couples the second PTT contact to the voltage level to which the common contact of the PTT switch is coupled by coupling the second PTT contact to the voltage level to which the common contact of PTT switch is coupled through a resistor of a predetermined impedance in response to detecting that the PTT switch has been operated to the first non-center position at a time when the PTT circuit detects no indication of the first audio device being coupled to the first connector, and detects an indication that the second audio device is an ICS coupled to the second connector. 
 
     
     
       5. The apparatus of  claim 4 , wherein the voltage level to which the common contact of the PTT switch is coupled is a ground conveyed by a ground conductor. 
     
     
       6. The apparatus of  claim 5 , wherein the indication of the second audio device being an ICS coupled to the second connector is the second connect contact being coupled to a voltage higher than the ground conveyed by the ground conductor, and wherein the predetermined impedance of the resistor is 470 ohms. 
     
     
       7. A method of augmenting the function of an apparatus comprises a push-to-talk (PTT) switch having a center position, operable to a first non-center position from the center position to engage a PTT function of an audio device coupled to a first connector of the apparatus, and operable to a second non-center position from the center position to engage a PTT function of an audio device coupled to a second connector of the apparatus, the method comprising:
 monitoring the first connector for an indication of a first audio device being coupled to the first connector; 
 engaging a PTT function of a second audio device coupled to a second connector in response to detecting that the PTT switch being operated to the first non-center position at a time when no indication of the first audio device being coupled to the first connector is detected; and 
 refraining from engaging the PTT function of the second audio device coupled in response to detecting the PTT switch being operated to the first non-center position at a time when an indication of the first audio device being coupled to the first connector is detected. 
 
     
     
       8. The method of  claim 7 , wherein engaging a PTT function of a second audio device coupled to the second connector in response to detecting the PTT switch being operated to the first non-center position at a time when no indication of the first audio device being coupled to the first connector is detected comprises coupling a contact of the second connector to a ground conveyed by a ground conductor. 
     
     
       9. The method of  claim 8 , further comprising:
 monitoring the second connector for an indication of the second audio device being an intercom system (ICS) coupled to the second connector; and 
 modifying the manner in which the PTT circuit couples the contact of the second connector to the ground conveyed by the ground conductor by coupling the contact of the second connector to the ground conveyed by a ground conductor through a resistor of a predetermined impedance in response to detecting the PTT switch being operated to the first non-center position at a time when there is no indication of the first audio device being coupled to the first connector, and an indication that the second audio device is an ICS coupled to the second connector is detected.